_Saudi Aramco Engineering Standard

Document Responsibility: VesselsSAES-D-109

Issue Date: 29 December 2004

Next Planned Update: 1 January 2006Design of Small Tanks

Page 18 of 18

Previous Issue: 30 November 2003 Next Planned Update: 1 January 2006

Revised paragraphs are indicated in the right marginPage 1 of 18

Primary contact: Mahmoud Y. Naffa'a on 874-7263

Engineering Standard

SAES-D-10929 December 2004

Design of Small Tanks (BLUE-LINED VERSION)

Vessels Standards Committee Members

Naffa'a, M.Y., Chairman

Al-Anizi, S.S.

Al-Gahtani, M.S.

Al-Musaiid, H.A.

Al-Sharhan, Z.S.

Jones, S.B.

Khanna, R.K.

Khouie, S.B.

Kim, S.U.

Muir, W.R.

Walsh, M.P.

Saudi Aramco DeskTop Standards

Table of Contents

1Scope.............................................................2

2Conflicts and Deviations................................2

3References.....................................................2

4Definitions......................................................4

5Responsibilities..............................................5

6Tank Selection...............................................5

7Materials........................................................6

8Design.........................................................6

9Appurtenances............................................8

10Coatings and Painting..................................10

11Insulation......................................................10

12Grounding....................................................10

13Cathodic Protection......................................11

14Foundations.................................................11

15Drawings, Calculations, and Data................11

Appendix I..........................................................12

Appendix II.........................................................14

Appendix III........................................................15

Appendix IV........................................................17

1Scope

1.1This standard defines the minimum mandatory requirements governing the design and selection of small atmospheric pressure storage tanks used in production, process plant, bulk plant, building services, fuel dispensing, or community facilities applications.

1.1.1This standard shall not be attached to nor made a part of purchase orders.

1.1.2The selection and design of field-erected atmospheric pressure storage tanks in accordance with API STD 650, Appendix J shall be in accordance with SAES-D-100.

1.2This standard covers tanks used for the aboveground or underground storage of flammable and combustible liquids. It also covers tanks used for the storage of chemicals and water.

1.3Tanks designed in accordance with this standard shall be limited to a maximum capacity given by the relevant industry standards listed in Paragraph 3.2.

1.4This standard shall be used by the Design Engineer to complete the tank data sheets.

2Conflicts and Deviations

2.1Any conflicts between this standard and other Saudi Aramco Engineering Standards (SAESs), Saudi Aramco Materials System Specifications (SAMSSs), industry codes and standards, and Saudi Aramco Standard Drawings (SASDs) and Forms shall be resolved in writing by the Company or Buyer Representative through the Manager, Consulting Services Department of Saudi Aramco, Dhahran.

2.2Direct all requests to deviate from this standard in writing to the Company or Buyer Representative, who shall follow internal company procedure SAEP-302 and forward such requests to the Manager, Consulting Services Department of Saudi Aramco, Dhahran.

3References

The selection and design of equipment and facilities covered by this standard shall comply with the latest edition of the references listed below, unless otherwise noted.

3.1Saudi Aramco References

Saudi Aramco Engineering Procedure

SAEP-302Instructions for Obtaining a Waiver of a Mandatory Saudi Aramco Engineering Requirement

Saudi Aramco Engineering Standards

SAES-A-005Safety Instruction Sheets

SAES-A-112Meteorological Data

SAES-B-005Spacing and Diking For Atmospheric and Low-Pressure Tanks

SAES-B-054Access, Egress, and Materials Handling for Plant Facilities

SAES-B-055Plant Layout

SAES-D-100Design Criteria of Atmospheric and Low-Pressure Tanks

SAES-H-001Selection Requirements for Industrial Coatings

SAES-H-101Approved Protective Coating System

SAES-J-300Level

SAES-N-001Insulation

SAES-P-111Grounding

SAES-Q-005Concrete Foundations

SAES-X-500Cathodic Protection of Vessels and Tank Internals

SAES-X-600Cathodic Protection of Plant Facilities

Saudi Aramco Materials System Specification

32-SAMSS-030Manufacture of Small Tanks

Saudi Aramco Standard Drawings

AA-036355Impressed Current Tank Bottom, Cathodic Protection Details

AB-036387Grounding

Saudi Aramco Forms and Data Sheets

2693-ENGTank Safety Instruction Sheet

2696-ENGAppurtenance Schedule and Orientations

3.2Industry Codes and Standards

(CO, LL) KNOW SMALL TANK SELECTION REQUIREMENTS AT SA (See Ch 6)

SEVEN TYPES OF SMALL TANKS EXIST AT SA FOR DESIGN PURPOSES

SEE SAES-D-100 for API 620 & 650 TANKS KNOW YOUR TANK SCOPE!!!

American Petroleum Institute

1-API STD 650Welded Steel Tanks for Oil Storage

2-API SPEC 12FSpecification for Shop Welded Tanks for Storage of Production Liquids

3-API SPEC 12PSpecification for Fiberglass Reinforced Plastic Tanks

American Water Works Association

4-AWWA D100Welded Steel Tanks for Water Storage

5-AWWA D120Thermosetting Fiberglass-Reinforced Plastic Tanks

Underwriters Laboratories, Inc.

6-UL 142Steel Aboveground Tanks for Flammable and Combustible Liquids

7-UL 1316Glass-Fiber-Reinforced Plastic Underground Storage Tanks for Petroleum Products, Alcohols, and Alcohol-Gasoline Mixtures

4Definitions

Atmospheric Pressure: Internal pressure that does not exceed the weight of the tank roof.

Design Engineer: The Engineering Company responsible for specifying, on the design data sheet, the design requirements for tanks.

Combustible Liquid: A liquid that has a flash point greater than 54C and that is at a temperature lower than 8C below its flash point.

Flammable liquid: A liquid that has a flash point equal to or less than 54C.

Saudi Aramco Engineer: The Supervisor of the Piping and Mechanical Unit, Consulting Services Department, Dhahran.

Small Tanks: Shop fabricated or field erected atmospheric pressure storage tanks up to 1500 barrels capacity.

Tank Manufacturer: The Company responsible for the design and fabrication of tanks

5Responsibilities

5.1The Design Engineer is responsible for specifying the type, size and design conditions for storage tanks, including the requirements for associated tank appurtenances.

5.2The Tank Manufacturer is responsible for the design, supply of materials, fabrication, erection, inspection, testing, surface preparation and painting of tanks in accordance with the Design Engineer's specification.

6Tank Selection

6.1Aboveground, vertical, cylindrical, steel tanks to be used for the storage of production liquids and located within producing facilities shall be in accordance with the following.

(1)API SPEC 12F or UL 142 up to 750 barrels capacity.

(2)API STD 650, Appendix J or UL 142 for over 750 and up to 1500 barrels capacity.

(3)The Design Engineer shall use the most economical selection from the standards specified in each case.

6.2API STD 650, Appendix J or UL 142, shall be used for aboveground, steel tanks used for the storage of crude oil, hydrocarbon intermediates, chemicals, or final products and located within process plants, bulk plants, buildings, fuel dispensing or community facilities. The choice of the appropriate standard shall be based on the following.

(1)Either API STD 650 Appendix J or UL 142 may be used for tanks storing liquids that have a specific gravity not greater than that of water. The Design Engineer shall elect the more economical option between these standards for each application.

(2)API STD 650 Appendix J shall be used for tanks storing liquids that have a specific gravity greater than that of water.

(3)UL 142 shall be used for aboveground stainless steel tanks.

6.3Underground, fiberglass reinforced plastic tanks to be used for the storage of petroleum products shall be in accordance with UL 1316.

6.4Aboveground, vertical, cylindrical, fiberglass reinforced plastic tanks to be used for the storage of petroleum products, alcohol-gasoline mixtures, or corrosive chemicals shall be in accordance with API SPEC 12P.

6.5Aboveground steel tanks to be used for the storage of water shall be in accordance with AWWA D100.

6.6Aboveground fiberglass reinforced plastic tanks to be used for the storage of water shall be in accordance with AWWA D120.

6.7Fiberglass reinforced plastic tanks shall comply with the restrictions of SAES-B-055, Section 8.7 on their use.

6.8Steel tanks used for the storage of flammable or combustible liquids and located within production facilities, process plants, or bulk plants shall be installed aboveground.

6.9Fiberglass reinforced plastic tanks used for the storage of flammable or combustible liquids and located within fuel dispensing or community facilities shall be located underground.

7Materials

7.1The Design Engineer shall specify material requirements based on the specific tank service.

7.2The Design Engineer shall specify a corrosion allowance for unlined carbon and low-alloy steel tanks based on the anticipated service life and corrosivity of the liquids to be stored.

7.3Materials proposed by the Tank Manufacturer shall be selected in accordance with 32-SAMSS-030.

8Design

8.1General

8.1.1The Design Engineer shall complete the Storage Tank Data Sheet for the tank being purchased in accordance with this standard as follows:

(1)API SPEC 12F tanks: Complete the Storage Tank Data Sheet in Appendix I of this standard.

(2)API STD 650 Appendix J tanks: Use the Storage Tank Data Sheet in Appendix L of API STD 650 and provide the information as detailed in Appendix II of this standard.

(3)UL 142 tanks: Complete the Storage Tank Data Sheet provided in Appendix III of this standard.

(4)API SPEC 12P tanks: Use Data Sheet 1 of API SPEC 12P and provide the information as detailed in Appendix IV of this standard.

(5)UL 1316 tanks: Complete the Storage Tank Data Sheet provided in Appendix III of this standard.

(6)AWWA D100 tanks: Use Section III or Section IV in the Forward of AWWA D100 as applicable and provide the required information.

(7)AWWA D120 tanks: Complete the Storage Tank Data Sheet as provided in Appendix III of this standard.

8.1.2The Design Engineer shall complete Form SA 2696-ENG showing the tank dimensions, appurtenance schedules, orientations and elevations.

8.1.3The Design Engineer shall complete tank Safety Instruction Sheets in accordance with SAES-A-005.

8.2Design Criteria

Storage tanks within the scope of this standard shall be designed, fabricated, inspected and tested in accordance with the applicable industry standard listed in Paragraph 3.2 of this standard and 32-SAMSS-030.

8.3Tank Dimensions and Capacity

8.3.1The Design Engineer shall determine the initial tank dimensions based on the most economical tank height (or length) versus diameter.

8.3.2The Design Engineer shall verify that the Tank Manufacturer's design proposal meets the specified dimensional requirements.

8.4Design Conditions

The design temperature shall be the maximum operating temperature of the tank.

8.5External Loads

8.5.1The basic wind speed corresponding to the tank site shall be specified in accordance with SAES-A-112.

8.5.2The seismic zone factor, importance factor and the site coefficient corresponding to the tank site shall be specified in accordance with SAES-A-112.

8.5.3Underground tanks shall be designed for soil, traffic and/or buoyancy loads as applicable.

8.5.4Loads superimposed by platforms and brackets and loads resulting from connected piping shall be considered in the tank design.

8.6Under-tank leak detection and sub-grade protection shall be provided for aboveground, vertical flat bottom steel tank supported directly on soil foundation according to API STD 650, Appendix I. Acceptable construction details are Figures I-1, I-2, I-3, I-8, I-9 and I-10. Flexible membrane liner of minimum 1000 microns (40 mils) thickness compatible with the stored product shall be specified under the tank bottom. The liner shall be placed at the bottom of the ring foundation or minimum 1 meter below the top edge of the ring foundation whichever is greater. The liner shall extend to the internal top edge of the ring foundation. Alternative under-tank leak detection and sub-grade protection systems shall not be permitted without the prior approval of the Saudi Aramco Engineer.

9Appurtenances

9.1General

The type, quantity and layout of all appurtenances for storage tanks shall be specified in accordance with this standard.

9.2Nozzles and Manways

9.2.1Nozzle and piping sizes 1- inch, 2- inch, 3- inch and 5 inch NPS shall not be used.

9.2.2Nozzles 2 inch NPS and larger shall be flanged.

9.2.3Connections 1- inch NPS and smaller, other than welding outlets and welding bosses, shall be Class 3000 minimum, either socket welded or threaded couplings.

9.2.4Connections 1- inch NPS and smaller shall be gusseted to prevent potential physical damage during handling and shipping.

9.2.5Manways for aboveground, vertical cylindrical tanks shall be specified as follows.

(1)One 24 inch NPS shell manway.

(2)One 20 inch NPS roof manway for tanks larger than 10,000 gallons capacity.

(3)A cleanout opening, when provided in accordance with the requirements of the relevant standard or specification, may be substituted for the shell manway.

9.2.6One 20 inch NPS manway shall be provided for aboveground or underground horizontal cylindrical tanks.

9.3Vents

The Design Engineer shall verify the adequacy of the number and size of the vents proposed by the Tank Manufacturer. Provision of frangible joint at the shell-to-roof juncture for aboveground vertical steel tanks for emergency venting is prohibited.

9.4Temperature Instruments

9.4.1Dial thermometers shall be specified, when required by the Operating Unit at the specific facility. The size and location of thermometers shall be shown on Form SA 2696-ENG.

9.4.2Tanks with heaters shall be equipped with a self-actuating temperature controller, unless the inlet steam temperature is such that the condensing temperature will not exceed the process needs. The location of the sensing point for the controller shall be the same as for a dial thermometer.

9.5Level Gauging Systems

9.5.1Level gauging systems shall be specified in accordance with SAES-J-300.

9.5.2A minimum of one level gauging instrument per tank, readable either from grade or from an access platform, shall be specified.

9.5.3Provisions for manual gauging shall be specified, even if the tank is provided with an automatic gauging device.

9.6Sample Connections

9.6.1Sample connections shall be specified, when required by the Operating Unit at the specific facility.

9.6.2The number, size and location of sample connections shall be shown on Form SA 2696-ENG.

9.7Stairways, Ladders and Platforms

9.7.1Stairways, ladders and platforms shall be specified in accordance with SAES-B-054.

9.7.2Access to the roof of aboveground, vertical, cylindrical, tanks shall be provided as follows.

(1)A spiral stairway shall be specified for tanks over 6 m in height and for tanks requiring gauging or sampling from the roof. A platform shall also be specified for access to the gauge or sampling hatch.

(2)A vertical ladder shall be specified for tanks that do not require spiral stairways.

(3)Stairs shall be located on the upwind side with respect to the prevailing wind direction of vertical tanks in hydrocarbon services, and this shall be shown on Form SA 2696-ENG. However, where it is impractical to meet this requirement, only the upper stairway landing is required to be located upwind side of the tank.

10Coatings and Painting

10.1Surface preparation and painting specifications shall be selected in accordance with SAES-H-001.

10.2The Design Engineer shall specify all painting requirements on the Storage Tank Data Sheet in accordance with SAES-H-101, including the Approved Protective Coating Systems (APCS), surface preparation, primer type, number of coats, total thickness and the areas or parts of the tank to be painted.

11Insulation

11.1The Design Engineer shall specify the type and thickness of external insulation for above ground tanks in accordance with SAES-N-001, where required.

11.2The Design Engineer shall specify whether aboveground tanks must be insulated to protect them from fire exposure based on tank location or when required by the Operating Unit.

12Grounding

The Design Engineer shall specify the grounding requirements in accordance with SAES-P-111 and standard drawing AB-036387.

13Cathodic Protection

Cathodic protection requirements shall be in accordance with SAES-X-500 and SAES-X-600.

14Foundations

14.1Spacing and diking of tanks shall be in accordance with SAES-B-005.

14.2Concrete foundations for tanks shall be in accordance with SAES-Q-005.

14.3Under Tank Leak Detection and Sub-grade Protection (CO, for AG Tanks)

14.3.1Tanks in services other than water shall be provided with an under tank leak detection and sub-grade protection according to API STD 650, Appendix I. Acceptable construction details are Figures I-1, I-2, I-3, I-8, I-9 and I-10.

14.3.2Flexible membrane liner of minimum 1000 microns (40 mils) thickness compatible with the stored product shall be specified under the tank bottom. The liner shall be placed according to SASD AA-036355, extending to the internal top edge of the ring foundation.

14.3.3Joints in the liner shall satisfy the leak tightness, permeability, and chemical resistance requirements for the liner material.

14.3.4Alternative under-tank leak detection and sub-grade protection systems shall not be permitted without the prior approval of the Saudi Aramco Engineer.

15Drawings, Calculations, and Data

15.1The Design Engineer shall complete the Storage Tank Data Sheet and forms to the extent specified in this standard.

15.2The Design Engineer is responsible for completion of applicable portions of the Tank Safety Instruction Sheet (Form SA 2693-ENG) in accordance with the data provided by the Tank Manufacturer and SAES-A-005.

Revision Summary

29 December 2004Revised the "Next Planned Update". Reaffirmed the contents of the document, and reissued with no other changes.

Appendix I

Data Sheet for Storage Tanks DesignedIn Accordance with API SPEC 12F

1.Tank Location:

Name of Plant:__________________________

Location:__________________________

2.Tank No._____________

Nominal Capacity_____________ Gallons/Barrels

Outside Diameter_____________ m

Height_____________ m

3.Type of Bottom:____________

Flat:____________

Unskirted Cone:____________

Skirted Cone:____________

4.Corrosion Allowance: ____________ mm

5.Shell Plate Thickness: ____________ mm

Specify as 6 mm plus corrosion allowance in excess of 1.6 mm.

6.Maximum Pumping Rates:

In______________ Barrels/Hour (Gallons/Hour)

Out______________ Barrels/Hour (Gallons/Hour)

7.Liquid Stored ____________ Design S.G. _____ at _____ C

Is this a viscous oil service?

Yes_____

No_____

8.Maximum Operating Temperature ___________ C

9.Wind Velocity ______________ km/h(mph)

10.Earthquake Zone ____________

Appendix I (Continued)

11.No. and Size of Shell Manholes_________________________

No. and Size of Roof Manholes_________________________

12.Shell Nozzles:

Inlet:No.__________Size:________________________

Outlet:No.__________Size________________________

13.Instrument Connections:

Level:No.___________Size___________________

Temperature:No.___________Size___________________

Sample:No.___________Size___________________

14.Is an anti-channel drain baffle required?

Yes_____

No_____

15.Is a downcomer pipe required?

Yes_____

No_____

16.Insulation _____________________________________________

17.Paint______________________________________

Internal Coating______________________________________

18.Stairway:Circular__________

Straight__________

Ladder:__________

19.Purchaser's Reference Documents:

SAMSSs____________________________________________

SASDs____________________________________________

Forms____________________________________________

Others____________________________________________

20.Remarks

_______________________________________________________

_______________________________________________________

Appendix II

Completion of API STD 650 Storage Tank Data SheetFor Appendix J - Shop-Assembled Storage Tanks

The Design Engineer shall complete the following portions of the tank data sheet:

1.Page 1 of Data Sheet

(1)All items on Page 1. Add Appendix J to Items 9 and 10.

(2)Item 5, the maximum pumping rates must be specified in order to properly size the vents.

2.Page 2 of Data Sheet

(1)Item 8, the details in API STD 650, Figure F-1, showing the horizontal leg of the roof support angle turning inward for cone roof tanks.

(2)Item 12, paint in accordance with Paragraph 10 of this standard

(3)Item 13, tank bottom coating, if required

(4)Item 18, mill test reports shall be required

(5)Item 19, applicable Saudi Aramco Standard Drawings and Forms shall be listed

(6)Item 21, 32-SAMSS-030 shall also be listed

3.Page 3 of Data Sheet

(1)Item 1, stairway style in accordance with this standard

(2)Items 8, 9, 10 and 11, number and size of shell and roof manholes, and shell and roof nozzles, in accordance with completed Form 2696-ENG for the tank.

(3)Other accessories, such as level gages, grounding lugs, etc., which are to be supplied by the Tank Manufacturer, shall also be included on the Storage Tank Data Sheet.

Appendix III

Data Sheet for Storage Tanks DesignedIn Accordance with UL 142, UL 1316, or AWWA D120

1.Tank Location:____________________________________________

Name of Plant:____________________________________________

Location:____________________________________________

2.Applicable Industry Standard:

UL 1316____________________

UL 142__________AWWA D120__________

4.Tank Material (For UL 142 tanks)

Carbon Steel_________

Stainless Steel_________

5.Tank No.____________

Nominal Capacity____________ Gallons/Barrels

Diameter____________ m

Height (Length):____________ m

6.Tank Geometry

Cylindrical:_________

Spherical:_________

Rectangular:_________

7.Tank Orientation:

Vertical:__________

Horizontal:__________

8.Maximum Pumping Rates:

In_________________Barrels/Hour (Gallons/Hour)

Out_________________Barrels/Hour (Gallons/Hour)

9.Liquid Stored _____________ Design S.G. _____ at _____ C

Corrosion Allowance _____________ mm

10.Wind Velocity______________km/h (mph)

Earthquake Zone______________

Appendix III (Continued)

Maximum Operating Temperature ___________ C

11.For UL 142 Tanks Only

Is Secondary Containment Required?

Yes_____

No _____

Stairway:Circular__________

Straight__________

Ladder:__________

12.No. and Size of Manholes_________________________

13.Shell Nozzles:

Inlet:No.__________Size_______________________

Outlet:No.__________Size_______________________

14.Instrument Connections:

Level:No.___________Size_______________________

Temperature:No.___________Size_______________________

Sample:No.___________Size_______________________

15.Insulation________________________________________________

16.Paint___________________________________________________

Internal Coating___________________________________________

17.Purchaser's Reference Documents:

SAMSSs________________________________________________

SASDs________________________________________________

Forms________________________________________________

Others________________________________________________

18.Remarks

_________________________________________________________

_________________________________________________________

Appendix IV

Completion of API SPEC 12PStorage Tank Data Sheet

The Design Engineer shall complete Design Data Sheet 1 of API SPEC 12P as necessary for the particular tank application. The entries noted below shall be completed as follows for all applications.

1.An API SPEC 12P Monogram is required.

2.If a ladder is required, it must be caged when required by SAES-B-054.